SpaceX CEO Elon Musk has said he'll consider it a win if his enormous new Falcon Heavy rocket even escapes the launch pad. Today, the rocket fired its engines in a test at the Kennedy Space Center in Florida, clearing the way for an inaugural launch in the coming weeks. Space scientists will be rooting for it, too. With its heavy-lift capability, the rocket can fling larger probes to distant planets more quickly—and, perhaps, more cheaply—than previous rockets.

"We can think about follow-up missions across the outer solar system, Mars sample return, even missions to Venus or Mercury," says planetary scientist Alan Stern of the Southwest Research Institute in Boulder, Colorado, who was also an independent consultant for SpaceX between 2010 and 2012.

Created by strapping together three of the company's Falcon 9 rockets, the Falcon Heavy is 70 meters tall, the most powerful rocket since the Saturn V that took humans to the moon. It is expected to carry up to 64,000 kilograms to low-Earth orbit, more than twice the payload of the biggest currently available vehicle, United Launch Alliance's (ULA's) Delta IV Heavy. Moreover, the new rocket's booster stages can be reused, which SpaceX claims will save money. It says a Falcon Heavy launch will start at a mere $90 million—less than 20% of the Delta IV Heavy's cost.

Such price tags could transform mission planning for NASA and other space agencies, Stern says. "You're talking about savings of hundreds of millions of dollars, which is sufficient to create whole new missions just from the savings." Of course, were NASA to save on launches, Congress could take that money and use it elsewhere, says Henry Hertzfeld, who studies space policy at The George Washington University in Washington, D.C. He adds that the launch fees that government agencies pay tend to be negotiated in long-term contracts, based on payload needs, and don't necessarily align with prices published on a company website.

The business case for Falcon Heavy involves taking commercial satellites cheaply to low-Earth orbit, and sending tourists on slingshots around the moon. But researchers have also been penciling the rocket into their plans ever since its design was unveiled in 2011. Studies for NASA's $2 billion Europa Clipper mission have often included the possibility of hitching a ride on one as a money-saving measure. The 3.6-ton probe, slated to launch as early as 2022, would conduct flybys of Jupiter's intriguing frozen moon to map its icy crust and subsurface ocean. Planners still expect it to fly on NASA's own heavy-lift vehicle, the nearly 100-meter-tall Space Launch System (SLS). But the first test launch of the SLS has slipped to 2020, and each launch is expected to cost about $1 billion.

Other possible targets for Falcon Heavy include Saturn's moons Titan and Enceladus and the ice giants Neptune and Uranus. Stern, who leads a NASA mission that flew past Pluto in 2015, says teams are considering using the rocket to send a probe with enough fuel to slow down and orbit the distant world. SpaceX has said that Falcon Heavy could deliver 2 to 4 tons to the surface of Mars—opening the way to more ambitious missions than the 1-ton Curiosity rover.

Astronomers are also thinking about what heavy lift can do for them. Each component of NASA's upcoming 6.2-ton James Webb Space Telescope, with a 6.5-meter mirror, had to be both lightweight and yet hardy enough to withstand rigorous shaking during launch, two often incompatible requirements. With Falcon Heavy's additional lift, researchers planning the Large UV Optical Infrared Surveyor telescope, a proposed mission for the 2020s with a mirror at least 9 meters across, could focus less on reducing weight and more on delivering a great scientific instrument, says Matt Mountain, president of the Association of Universities for Research in Astronomy in Washington, D.C. "If we don't have to fight for mass, the testing is greatly simplified and you can launch more ambitious systems."

SpaceX's big rocket will face competition in the coming years, and not just from the SLS. Another private company, Blue Origin, intends to debut its reusable New Glenn rocket in 2020, and ULA is working on a vehicle called Vulcan. The competition could lower prices for researchers, says Phil Larson, an aerospace expert at the University of Colorado in Boulder and a former communications director at SpaceX. "You could see not just governments having space programs, but private entities doing more in space, and maybe universities," he says.

Then again, the pool of heavy rockets will remain small for the foreseeable future, and researchers shouldn't expect rock-bottom prices anytime soon, Hertzfeld says. "This is not your Econ 1 definition of competition," he says. "It certainly should help NASA and others with prices, but how much that influences all of this is a study in and of itself."

SpaceX already has customers lining up, including the Saudi Arabian communications firm Arabsat, the London-based mobile services provider Inmarsat, and the U.S. Air Force. Its first payload will be something a bit more personal—Musk's own Tesla Roadster, painted midnight cherry and playing David Bowie's "Space Oddity."